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View Full Version : Controlling the speed of a motion channel...how?

Netvudu
02-06-2006, 06:23 PM
Ok, so I got this nice wing motion loop, and I use a expression to make the other one follow, and a slider to make the wings opening motion wider or narrower using a expression as well, which is a nice an elegant solution. So far so good.

Now, I want to use another slider to control the speed of the wings motion...uh...how. Itīs just one channel but I donīt know how to do it. Is there any expression which changes the speed of a motion channel? I really want this to be controllable through a slider.

Thanks.
PentamiterBeast
02-06-2006, 06:55 PM
Well, it depends exactly how you got your expressions set up, but you'd have to build into them a reference to a sub-expression, which would use the variable command "time" and reference another nulls position as a multiplier. Check the expression builder for details on how the time parameter works.
Netvudu
02-07-2006, 01:37 AM
Yah. Being there, done that. I mean, of course I thank you for your input, but thatīs the first thing I tried. Obviously I have to reference to a null channel as a multiplier, thatīs what I did to affect the wings opening motion, and surely I have to use a Time-related expression.

I also know how both, Time and Frame variables work and also tried subexpressions.
My problem seems to lie precisely there...I donīt seem to find how the exact expression syntax is. My brain refuses to think on how to affect a curve time-wise instead of value-wise....

By the way, the info on the expression builder about the Time variable is laughable at best, unless Iīm missing some obscure tab somewhere....
PentamiterBeast
02-07-2006, 02:18 AM
Ah, well, I must admit, Im not authority on it myself, though I did something similar about three years ago where I had a car moving slowly over uneven terrain, and used a similar trick to vary the speed of the side to side motion. I cant remember exactly how i did it (though I know I used expression with linked sub-ex in there) and the scene file is long gone, so I cant look it back up for ya. If I get chance, I'll have a quick play, and see if I can remember how I did it. Failing that, what a bout just making awhole cycle of flaps, then setting just the wing aprts as object (hierarchys, whatever) in motion mixer and using the timewarp curves in that (now this is me talking real theory, never got on with motion-mixer, so no practicaly knowledge.)
Netvudu
02-07-2006, 02:39 AM
yeah, that would be easy, but Iīm not just trying to get the thing done. Iīm trying to create a nifty setup and control the little wings with slider besides a whole bunch of other things going around, so forcing the animator to use Motion Mixer every time doesnīt sound too exciting.


But thanks again :)
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